Stop using SpawnedTestServer in DownloadContentTest.*

content/public/test/test_download_request_handler.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/public/test/test_download_request_handler.h"
+
+#include <inttypes.h>
+
+#include "base/logging.h"
+#include "base/memory/weak_ptr.h"
+#include "base/run_loop.h"
+#include "base/strings/stringprintf.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/base/io_buffer.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_response_headers.h"
+#include "net/url_request/url_request_filter.h"
+#include "net/url_request/url_request_interceptor.h"
+
+namespace content {
+
+namespace {
+
+using Parameters = TestDownloadRequestHandler::Parameters;
+using InjectedError = TestDownloadRequestHandler::InjectedError;
+
+// Intercepts URLRequests on behalf of TestDownloadRequestHandler. Necessarily
+// lives on the IO thread since that's where net::URLRequestFilter invokes the
+// URLRequestInterceptor.
+class TestDownloadRequestInterceptor : public net::URLRequestInterceptor {
+ public:
+  // Invoked on the IO thread to register a URLRequestInterceptor for |url|.
+  // Returns an IO-thread bound weak pointer for interacting with the
+  // interceptor.
+  static base::WeakPtr<TestDownloadRequestInterceptor> Register(
+      const GURL& url);
+
+  using JobFactory = base::Callback<net::URLRequestJob*(
+      net::URLRequest*,
+      net::NetworkDelegate*,
+      base::WeakPtr<TestDownloadRequestInterceptor>)>;
+
+  ~TestDownloadRequestInterceptor() override;
+
+  // Unregisters the URLRequestInterceptor. In reality it unregisters whatever
+  // was registered to intercept |url_|. Since |this| is owned by
+  // net::URLRequestFilter, unregistering the interceptor deletes |this| as a
+  // side-effect.
+  void Unregister();
+
+  // Change the URLRequestJob factory. Can be called multiple times.
+  void SetJobFactory(const JobFactory& factory);
+
+  // Sets |requests| to the vector of completed requests and clears the internal
+  // list. The returned requests are stored in the order in which they were
+  // reported as being complete (not necessarily the order in which they were
+  // received).
+  void GetAndResetCompletedRequests(
+      TestDownloadRequestHandler::CompletedRequests* requests);
+
+  // Can be called by a URLRequestJob to notify this interceptor of a completed
+  // request.
+  void AddCompletedRequest(
+      const TestDownloadRequestHandler::CompletedRequest& request);
+
+ private:
+  TestDownloadRequestInterceptor(const GURL& url);
+
+  // net::URLRequestInterceptor
+  net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const override;
+
+  TestDownloadRequestHandler::CompletedRequests completed_requests_;
+  GURL url_;
+  JobFactory job_factory_;
+  // mutable because MaybeInterceptRequest() is inexplicably const.
+  mutable base::WeakPtrFactory<TestDownloadRequestInterceptor>
+      weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(TestDownloadRequestInterceptor);
+};
+
+// A URLRequestJob that constructs a response to a URLRequest based on the
+// contents of a Parameters object. It can handle partial (i.e. byte range
+// requests). Created on and lives on the IO thread.
+class PartialResponseJob : public net::URLRequestJob {
+ public:
+  static net::URLRequestJob* Factory(
+      const Parameters& parameters,
+      net::URLRequest* request,
+      net::NetworkDelegate* delegate,
+      base::WeakPtr<TestDownloadRequestInterceptor> interceptor);
+
+  // URLRequestJob
+  void Start() override;
+  void GetResponseInfo(net::HttpResponseInfo* response_info) override;
+  int64 GetTotalReceivedBytes() const override;
+  bool GetMimeType(std::string* mime_type) const override;
+  int GetResponseCode() const override;
+  bool ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read) override;
+
+ private:
+  PartialResponseJob(scoped_ptr<Parameters> parameters,
+                     base::WeakPtr<TestDownloadRequestInterceptor> interceptor,
+                     net::URLRequest* url_request,
+                     net::NetworkDelegate* network_delegate);
+
+  ~PartialResponseJob() override;
+  void ReportCompletedRequest(int64_t transferred_content_length);
+  static void OnStartResponseCallbackOnPossiblyIncorrectThread(
+      base::WeakPtr<PartialResponseJob> job,
+      const std::string& headers,
+      net::Error error);
+  void OnStartResponseCallback(const std::string& headers, net::Error error);
+
+  // In general, the Parameters object can specify an explicit OnStart handler.
+  // In its absence or if the explicit OnStart handler requests the default
+  // behavior, this method can be invoked to respond to the request based on the
+  // remaining Parameters fields (as if there was no OnStart handler).
+  void HandleOnStartDefault();
+
+  // Respond Start() assuming that any If-Match or If-Range headers have been
+  // successfully validated. This handler assumes that there *must* be a Range
+  // header even though the spec doesn't strictly require it for If-Match.
+  bool HandleRangeAssumingValidatorMatch();
+
+  // Adds headers that describe the entity (Content-Type, ETag, Last-Modified).
+  // It also adds an 'Accept-Ranges' header if appropriate.
+  void AddCommonEntityHeaders();
+
+  // Schedules NotifyHeadersComplete() to be called and sets
+  // offset_of_next_read_ to begin reading. Since this interceptor is avoiding
+  // network requests, it schedules the NotifyHeadersComplete() call
+  // asynchronously in order to avoid unexpected re-entrancy.

[Randy Smith (Not in Mondays), 2015/11/17 22:21:42]

I don't understand this sentence; what does avoiding re-entrancy have to do with
avoiding network requests?

[asanka, 2015/11/23 22:04:59]

Had we hit the network, we are likely to block and end up completing
asynchronously. Since we've avoided all that blocking work, Start() can complete
synchronously. Instead of completing synchronously, PartialResponseJob is going
to post a message and simulate a asynchronous completion. This makes the call
behave slightly more like a real network request.

[Randy Smith (Not in Mondays), 2015/11/28 00:38:19]

Gotcha.  Suggestion, nit: add ".. is avoiding network requests *and hence may
complete synchronously*, it schedules ...".

[asanka, 2015/11/30 18:00:10]

Done.

+  void NotifyHeadersCompleteAndPrepareToRead();
+
+  scoped_ptr<Parameters> parameters_;
+
+  base::WeakPtr<TestDownloadRequestInterceptor> interceptor_;
+  net::HttpResponseInfo response_info_;
+  int64_t offset_of_next_read_ = -1;
+  int64_t requested_range_begin_ = -1;
+  int64_t requested_range_end_ = -1;
+  base::WeakPtrFactory<PartialResponseJob> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PartialResponseJob);
+};
+
+template <class T>
+void StoreValueAndInvokeClosure(const base::Closure& quit_closure,

[Randy Smith (Not in Mondays), 2015/11/17 22:21:42]

nitty nit: The name "quit_closure" presumes how this function will be used.

[asanka, 2015/11/23 22:04:59]

Renamed to 'closure'.

+                                T* value_receiver,
+                                T value) {
+  *value_receiver = value;
+  quit_closure.Run();
+}
+
+// Xorshift* PRNG from https://en.wikipedia.org/wiki/Xorshift

[Randy Smith (Not in Mondays), 2015/11/17 22:21:42]

Did not review except to validate that it looked appropriately arcane :-}.

[asanka, 2015/11/23 22:04:59]

:-P

+uint64_t XorShift64StarWithIndex(uint64_t seed, uint64_t index) {
+  const uint64_t kMultiplier = UINT64_C(2685821657736338717);
+  uint64_t x = seed * kMultiplier + index;
+  x ^= x >> 12;
+  x ^= x << 25;
+  x ^= x >> 27;
+  return x * kMultiplier;
+}
+
+void RespondToOnStartedCallbackWithStaticHeaders(
+    const std::string& headers,
+    const net::HttpRequestHeaders&,
+    const TestDownloadRequestHandler::OnStartResponseCallback& callback) {
+  callback.Run(headers, net::OK);
+}
+
+GURL GetNextURLForDownloadInterceptor() {
+  static int index = 0;
+  std::string url_string =
+      base::StringPrintf("https://%d.default.example.com/download/", ++index);
+  return GURL(url_string);
+}
+
+scoped_refptr<net::HttpResponseHeaders> HeadersFromString(
+    const std::string& headers_string) {
+  scoped_refptr<net::HttpResponseHeaders> headers =
+      new net::HttpResponseHeaders(net::HttpUtil::AssembleRawHeaders(
+          headers_string.c_str(), headers_string.size()));
+  return headers;
+}
+
+// static
+net::URLRequestJob* PartialResponseJob::Factory(
+    const Parameters& parameters,
+    net::URLRequest* request,
+    net::NetworkDelegate* delegate,
+    base::WeakPtr<TestDownloadRequestInterceptor> interceptor) {
+  return new PartialResponseJob(make_scoped_ptr(new Parameters(parameters)),
+                                interceptor, request, delegate);
+}
+
+PartialResponseJob::PartialResponseJob(
+    scoped_ptr<Parameters> parameters,
+    base::WeakPtr<TestDownloadRequestInterceptor> interceptor,
+    net::URLRequest* request,
+    net::NetworkDelegate* network_delegate)
+    : net::URLRequestJob(request, network_delegate),
+      parameters_(parameters.Pass()),
+      interceptor_(interceptor),
+      weak_factory_(this) {
+  DCHECK(parameters_.get());
+  DCHECK_LT(0, parameters_->size);
+  DCHECK_NE(-1, parameters_->pattern_generator_seed);
+}
+
+PartialResponseJob::~PartialResponseJob() {}
+
+void PartialResponseJob::Start() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DVLOG(1) << "Starting request for " << request()->url().spec();
+
+  if (parameters_->on_start_handler.is_null()) {
+    HandleOnStartDefault();
+    return;
+  }
+
+  DVLOG(1) << "Invoking custom OnStart handler.";
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(
+          parameters_->on_start_handler, request()->extra_request_headers(),
+          base::Bind(&PartialResponseJob::
+                         OnStartResponseCallbackOnPossiblyIncorrectThread,
+                     weak_factory_.GetWeakPtr())));
+}
+
+void PartialResponseJob::GetResponseInfo(net::HttpResponseInfo* response_info) {
+  *response_info = response_info_;
+}
+
+int64 PartialResponseJob::GetTotalReceivedBytes() const {
+  return offset_of_next_read_ - requested_range_begin_;
+}
+
+bool PartialResponseJob::GetMimeType(std::string* mime_type) const {
+  *mime_type = parameters_->content_type;
+  return !parameters_->content_type.empty();
+}
+
+int PartialResponseJob::GetResponseCode() const {
+  return response_info_.headers.get() ? response_info_.headers->response_code()
+                                      : 0;
+}
+
+bool PartialResponseJob::ReadRawData(net::IOBuffer* buf,
+                                     int buf_size,
+                                     int* bytes_read) {
+  *bytes_read = 0;
+  DVLOG(1) << "Preparing to read " << buf_size << " bytes";
+
+  // requested_range_begin_ == -1 implies that the body was empty.
+  if (offset_of_next_read_ > requested_range_end_ ||
+      requested_range_begin_ == -1) {
+    ReportCompletedRequest(requested_range_end_ - requested_range_begin_ + 1);
+    DVLOG(1) << "Done reading.";
+    return true;
+  }
+
+  int64_t range_end =
+      std::min(requested_range_end_, offset_of_next_read_ + buf_size - 1);
+
+  if (!parameters_->injected_errors.empty()) {
+    const InjectedError& injected_error = parameters_->injected_errors.front();
+
+    if (offset_of_next_read_ == injected_error.offset) {
+      int error = injected_error.error;
+      SetStatus(net::URLRequestStatus(net::URLRequestStatus::FAILED, error));
+      DVLOG(1) << "Returning error " << net::ErrorToString(error);
+      ReportCompletedRequest(injected_error.offset - requested_range_begin_);
+      parameters_->injected_errors.pop();
+      return false;
+    }
+
+    if (offset_of_next_read_ < injected_error.offset &&
+        injected_error.offset <= range_end)
+      range_end = injected_error.offset - 1;
+  }
+  int bytes_to_copy = (range_end - offset_of_next_read_) + 1;
+
+  TestDownloadRequestHandler::GetPatternBytes(
+      parameters_->pattern_generator_seed, offset_of_next_read_, bytes_to_copy,
+      buf->data());
+  DVLOG(1) << "Read " << bytes_to_copy << " bytes at offset "
+           << offset_of_next_read_;
+  offset_of_next_read_ += bytes_to_copy;
+  *bytes_read = bytes_to_copy;
+  return true;
+}
+
+void PartialResponseJob::ReportCompletedRequest(
+    int64_t transferred_content_length) {
+  if (interceptor_.get()) {
+    TestDownloadRequestHandler::CompletedRequest completed_request;
+    completed_request.transferred_content_length = transferred_content_length;
+    completed_request.request_headers = request()->extra_request_headers();
+    interceptor_->AddCompletedRequest(completed_request);
+  }
+}
+
+// static
+void PartialResponseJob::OnStartResponseCallbackOnPossiblyIncorrectThread(
+    base::WeakPtr<PartialResponseJob> job,
+    const std::string& headers,
+    net::Error error) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&PartialResponseJob::OnStartResponseCallback, job, headers,
+                 error));
+}
+
+void PartialResponseJob::OnStartResponseCallback(const std::string& headers,
+                                                 net::Error error) {
+  DVLOG(1) << "OnStartResponse invoked with error:" << error
+           << " and headers:" << std::endl
+           << headers;
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (headers.empty() && error == net::OK) {
+    HandleOnStartDefault();
+    return;
+  }
+
+  if (error != net::OK) {
+    NotifyStartError(net::URLRequestStatus::FromError(error));
+    return;
+  }
+
+  response_info_.headers = new net::HttpResponseHeaders(
+      net::HttpUtil::AssembleRawHeaders(headers.c_str(), headers.size()));
+  NotifyHeadersCompleteAndPrepareToRead();
+}
+
+void PartialResponseJob::HandleOnStartDefault() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  SetStatus(net::URLRequestStatus());
+
+  const net::HttpRequestHeaders& extra_headers =
+      request()->extra_request_headers();
+
+  DCHECK(request()->method() == "GET") << "PartialResponseJob only "
+                                          "knows how to respond to GET "
+                                          "requests";
+  std::string value;
+
+  // If the request contains an 'If-Range' header and the value matches our
+  // ETag, then try to handle the range request.
+  if (parameters_->support_byte_ranges &&
+      extra_headers.GetHeader(net::HttpRequestHeaders::kIfRange, &value) &&
+      value == parameters_->etag && HandleRangeAssumingValidatorMatch())
+    return;
+
+  if (parameters_->support_byte_ranges &&
+      extra_headers.GetHeader("If-Match", &value)) {
+    if (value == parameters_->etag && HandleRangeAssumingValidatorMatch())
+      return;
+
+    // Unlike If-Range, If-Match returns an error if the validators don't match.
+    response_info_.headers = HeadersFromString(
+        "HTTP/1.1 412 Precondition failed\r\n"
+        "Content-Length: 0\r\n");
+    requested_range_begin_ = requested_range_end_ = -1;
+    NotifyHeadersCompleteAndPrepareToRead();
+    return;
+  }
+
+  requested_range_begin_ = 0;
+  requested_range_end_ = parameters_->size - 1;
+  response_info_.headers =
+      HeadersFromString(base::StringPrintf("HTTP/1.1 200 Success\r\n"
+                                           "Content-Length: %" PRId64 "\r\n",
+                                           parameters_->size));
+  AddCommonEntityHeaders();
+  NotifyHeadersCompleteAndPrepareToRead();
+  return;
+}
+
+bool PartialResponseJob::HandleRangeAssumingValidatorMatch() {
+  const net::HttpRequestHeaders& extra_headers =
+      request()->extra_request_headers();
+
+  std::string range_header;
+  std::vector<net::HttpByteRange> byte_ranges;
+
+  // There needs to be a 'Range' header and it should have exactly one range.
+  // This server is not going to deal with multiple ranges.
+  if (!extra_headers.GetHeader(net::HttpRequestHeaders::kRange,
+                               &range_header) ||
+      !net::HttpUtil::ParseRangeHeader(range_header, &byte_ranges) ||
+      byte_ranges.size() != 1)
+    return false;
+
+  // The request may have specified a range that's out of bounds.
+  if (!byte_ranges[0].ComputeBounds(parameters_->size)) {
+    response_info_.headers = HeadersFromString(
+        base::StringPrintf("HTTP/1.1 416 Range not satisfiable\r\n"
+                           "Content-Range: bytes */%" PRId64 "\r\n"
+                           "Content-Length: 0\r\n",
+                           parameters_->size));
+    requested_range_begin_ = requested_range_end_ = -1;
+    NotifyHeadersCompleteAndPrepareToRead();
+    return true;
+  }
+
+  requested_range_begin_ = byte_ranges[0].first_byte_position();
+  requested_range_end_ = byte_ranges[0].last_byte_position();
+  response_info_.headers =
+      HeadersFromString(base::StringPrintf(
+          "HTTP/1.1 206 Partial content\r\n"
+          "Content-Range: bytes %" PRId64 "-%" PRId64 "/%" PRId64 "\r\n"
+          "Content-Length: %" PRId64 "\r\n",
+          requested_range_begin_, requested_range_end_, parameters_->size,
+          (requested_range_end_ - requested_range_begin_) + 1));
+  AddCommonEntityHeaders();
+  NotifyHeadersCompleteAndPrepareToRead();
+  return true;
+}
+
+void PartialResponseJob::AddCommonEntityHeaders() {
+  if (parameters_->support_byte_ranges)
+    response_info_.headers->AddHeader("Accept-Ranges: bytes");
+
+  if (!parameters_->content_type.empty())
+    response_info_.headers->AddHeader(base::StringPrintf(
+        "Content-Type: %s", parameters_->content_type.c_str()));
+
+  if (!parameters_->etag.empty())
+    response_info_.headers->AddHeader(
+        base::StringPrintf("ETag: %s", parameters_->etag.c_str()));
+
+  if (!parameters_->last_modified.empty())
+    response_info_.headers->AddHeader(base::StringPrintf(
+        "Last-Modified: %s", parameters_->last_modified.c_str()));
+}
+
+void PartialResponseJob::NotifyHeadersCompleteAndPrepareToRead() {
+  std::string normalized_headers;
+  response_info_.headers->GetNormalizedHeaders(&normalized_headers);
+  DVLOG(1) << "Notify ready with headers:\n" << normalized_headers;
+
+  offset_of_next_read_ = requested_range_begin_;
+
+  // Flush out injected_errors that no longer apply. We are going to skip over
+  // ones where the |offset| == |requested_range_begin_| as well. While it
+  // prevents injecting an error at offset 0, it makes it much easier to set up
+  // parameter sets for download resumption. It means that when a request is
+  // interrupted at offset O, a subsequent request for the range O-<end> won't
+  // immediately interrupt as well. If we don't exclude interruptions at
+  // relative offset 0, then test writers would need to reset the parameter
+  // prior to each resumption rather than once at the beginning of the test.
+  while (!parameters_->injected_errors.empty() &&
+         parameters_->injected_errors.front().offset <= requested_range_begin_)
+    parameters_->injected_errors.pop();
+
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(&PartialResponseJob::NotifyHeadersComplete,
+                            weak_factory_.GetWeakPtr()));
+}
+
+// static
+base::WeakPtr<TestDownloadRequestInterceptor>
+TestDownloadRequestInterceptor::Register(const GURL& url) {
+  DCHECK(url.is_valid());
+  scoped_ptr<TestDownloadRequestInterceptor> interceptor(
+      new TestDownloadRequestInterceptor(url));
+  base::WeakPtr<TestDownloadRequestInterceptor> weak_reference =
+      interceptor->weak_ptr_factory_.GetWeakPtr();
+  net::URLRequestFilter* filter = net::URLRequestFilter::GetInstance();
+  filter->AddUrlInterceptor(url, interceptor.Pass());
+  return weak_reference;
+}
+
+void TestDownloadRequestInterceptor::Unregister() {
+  net::URLRequestFilter* filter = net::URLRequestFilter::GetInstance();
+  filter->RemoveUrlHandler(url_);
+  // We are deleted now since the filter owned |this|.
+}
+
+void TestDownloadRequestInterceptor::SetJobFactory(
+    const JobFactory& job_factory) {
+  job_factory_ = job_factory;
+}
+
+void TestDownloadRequestInterceptor::GetAndResetCompletedRequests(
+    TestDownloadRequestHandler::CompletedRequests* requests) {
+  requests->clear();
+  completed_requests_.swap(*requests);
+}
+
+void TestDownloadRequestInterceptor::AddCompletedRequest(
+    const TestDownloadRequestHandler::CompletedRequest& request) {
+  completed_requests_.push_back(request);
+}
+
+TestDownloadRequestInterceptor::TestDownloadRequestInterceptor(const GURL& url)
+    : url_(url), weak_ptr_factory_(this) {}
+
+TestDownloadRequestInterceptor::~TestDownloadRequestInterceptor() {}
+
+net::URLRequestJob* TestDownloadRequestInterceptor::MaybeInterceptRequest(
+    net::URLRequest* request,
+    net::NetworkDelegate* network_delegate) const {
+  DVLOG(1) << "Intercepting request for " << request->url()
+           << " with headers:\n" << request->extra_request_headers().ToString();
+  if (job_factory_.is_null())
+    return nullptr;
+  return job_factory_.Run(request, network_delegate,
+                          weak_ptr_factory_.GetWeakPtr());
+}
+
+}  // namespace
+
+struct TestDownloadRequestHandler::InterceptorProxy {
+  base::WeakPtr<TestDownloadRequestInterceptor> interceptor_;
+};
+
+TestDownloadRequestHandler::InjectedError::InjectedError(int64_t offset,
+                                                         net::Error error)
+    : offset(offset), error(error) {}
+
+// static
+Parameters TestDownloadRequestHandler::Parameters::WithSingleInterruption() {
+  Parameters parameters;
+  parameters.injected_errors.push(
+      InjectedError(parameters.size / 2, net::ERR_CONNECTION_RESET));
+  return parameters;
+}
+
+TestDownloadRequestHandler::Parameters::Parameters()
+    : etag("abcd"),
+      last_modified("Tue, 15 Nov 1994 12:45:26 GMT"),
+      content_type("application/octet-stream"),
+      size(102400),
+      pattern_generator_seed(1),
+      support_byte_ranges(true) {}
+
+TestDownloadRequestHandler::Parameters::~Parameters() {}
+
+void TestDownloadRequestHandler::Parameters::ClearInjectedErrors() {
+  std::queue<InjectedError> empty_error_list;
+  injected_errors.swap(empty_error_list);
+}
+
+TestDownloadRequestHandler::TestDownloadRequestHandler()
+    : TestDownloadRequestHandler(GetNextURLForDownloadInterceptor()) {}
+
+TestDownloadRequestHandler::TestDownloadRequestHandler(const GURL& url)
+    : url_(url) {
+  interceptor_proxy_.reset(new InterceptorProxy);
+  base::RunLoop run_loop;
+  BrowserThread::PostTaskAndReplyWithResult(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TestDownloadRequestInterceptor::Register, url_),
+      base::Bind(&StoreValueAndInvokeClosure<
+                     base::WeakPtr<TestDownloadRequestInterceptor>>,
+                 run_loop.QuitClosure(), &interceptor_proxy_->interceptor_));
+  run_loop.Run();
+}
+
+void TestDownloadRequestHandler::StartServing(const Parameters& parameters) {
+  TestDownloadRequestInterceptor::JobFactory job_factory =
+      base::Bind(&PartialResponseJob::Factory, parameters);
+  // Interceptor, if valid, is already registered and serving requests. We just
+  // need to set the correct job factory for it to start serving using the new
+  // parameters.
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TestDownloadRequestInterceptor::SetJobFactory,
+                 interceptor_proxy_->interceptor_, job_factory));
+}
+
+void TestDownloadRequestHandler::StartServingStaticResponse(
+    const base::StringPiece& headers) {
+  Parameters parameters;
+  parameters.on_start_handler = base::Bind(
+      &RespondToOnStartedCallbackWithStaticHeaders, headers.as_string());
+  StartServing(parameters);
+}
+
+// static
+void TestDownloadRequestHandler::GetPatternBytes(int seed,
+                                                 int64_t starting_offset,
+                                                 int length,
+                                                 char* buffer) {
+  int64_t seed_offset = starting_offset / sizeof(int64_t);
+  int64_t first_byte_position = starting_offset % sizeof(int64_t);
+  while (length > 0) {
+    uint64_t data = XorShift64StarWithIndex(seed, seed_offset);
+    int length_to_copy =
+        std::min(length, static_cast<int>(sizeof(data) - first_byte_position));
+    memcpy(buffer, reinterpret_cast<char*>(&data) + first_byte_position,
+           length_to_copy);
+    buffer += length_to_copy;
+    length -= length_to_copy;
+    ++seed_offset;
+    first_byte_position = 0;
+  }
+}
+
+TestDownloadRequestHandler::~TestDownloadRequestHandler() {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TestDownloadRequestInterceptor::Unregister,
+                 interceptor_proxy_->interceptor_));
+}
+
+void TestDownloadRequestHandler::GetCompletedRequestInfo(
+    TestDownloadRequestHandler::CompletedRequests* requests) {
+  base::RunLoop run_loop;
+  BrowserThread::PostTaskAndReply(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TestDownloadRequestInterceptor::GetAndResetCompletedRequests,
+                 interceptor_proxy_->interceptor_, requests),
+      run_loop.QuitClosure());
+  run_loop.Run();
+}
+
+}  // namespace content